Analog Devices Inc. AD7440BRM-REEL7

Overview

AD7440BRM-REEL7 from Analog Devices is a 10-bit, 1 MSPS successive approximation register (SAR) analog-to-digital converter with fully differential analog inputs, operating from single 3 V or 5 V supplies. It delivers 61 dB SINAD at 100 kHz input frequency, ±0.5 LSB INL, and 4 mW max power dissipation at 3 V/1 MSPS, targeting precision data acquisition in space-constrained systems.

For engineers reviewing the AD7440BRM-REEL7 datasheet, AD7440BRM-REEL7 pinout, AD7440BRM-REEL7 application, or AD7440BRM-REEL7 equivalent, key selection criteria include its 8-lead SOT-23 package, SPI/QSPI/MICROWIRE-compatible serial interface, differential track-and-hold architecture with 200 ns acquisition time, and support for externally adjustable reference voltages from 100 mV to 2.2 V (3 V supply) or 3.5 V (5 V supply).

Technical Context

The AD7440BRM-REEL7 implements a SAR ADC core with no pipeline delay, enabling deterministic conversion timing controlled by CS and SCLK. Its differential track-and-hold amplifier supports input frequencies up to 3.5 MHz and full-scale bandwidth of 2.5 MHz (–0.1 dB), with common-mode voltage set by VREF.

Conversion is initiated on the falling edge of CS; data is clocked out MSB-first on SDATA with four leading zeros followed by 10-bit twos-complement result and two trailing zeros. Power-down mode draws ≤1 μA, and serial clock speed directly governs throughput and dynamic power consumption.

Key Specifications

Pinout & Package

AD7440BRM-REEL7 is housed in an 8-lead SOT-23 package (JEDEC MO-178AA), with exposed pad not connected internally. Pin 1 is marked via laser scribe or mold index; device orientation follows standard SOT-23 top-view labeling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SAR ADC applications.

Compared with AD7440BRM-REEL7, AD7450ABRMZ-REEL7 offers 2 extra bits and 9 dB better SINAD at identical speed and footprint, while ADS8325IDR trades speed for 6-bit resolution gain and enhanced DC specs in a larger package-enabling trade-off decisions between bandwidth, precision, and board space.

Availability

AD7440BRM-REEL7 is available at Aetrix Electronics and suitable for transducer interface, battery-powered instrumentation, and motor control applications requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for AD7440BRM-REEL7 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The AD7440BRM-REEL7 belongs to the AD7440/AD7450A family of low-power, high-speed SAR ADCs designed specifically for space-constrained, battery-sensitive applications demanding differential input flexibility and deterministic timing.

FAQ

What is the maximum sampling rate supported by the AD7440BRM-REEL7?

The AD7440BRM-REEL7 supports a maximum throughput rate of 1 MSPS, achieved with an 18 MHz serial clock and 16 SCLK cycles per conversion. At this rate, conversion time is fixed at 888 ns, and the device maintains specified AC performance including 61 dB SINAD at 100 kHz input frequency. Lower rates are achievable by reducing SCLK frequency, which proportionally decreases dynamic power consumption.

Does the AD7440BRM-REEL7 require an external reference voltage?

Yes, the AD7440BRM-REEL7 requires an external reference voltage applied to the VREF pin. For specified performance, VREF must be 2.0 V (±1%) with a 3 V supply or 2.5 V (±1%) with a 5 V supply. The device operates functionally with VREF as low as 100 mV (3 V supply) or up to 2.2 V (3 V) / 3.5 V (5 V), enabling flexible input span configuration. A minimum 0.1 µF decoupling capacitor is required between VREF and GND.

What serial interface protocols is the AD7440BRM-REEL7 compatible with?

The AD7440BRM-REEL7 features an SPI-compatible serial interface that also supports QSPI™, MICROWIRE™, and generic DSP host connections. Data is clocked out MSB-first on the SDATA pin on the falling edge of SCLK, with a 16-bit frame format: four leading zeros, ten 10-bit twos-complement data bits, and two trailing zeros. No additional protocol translation or level-shifting is required for interoperability with standard microcontrollers.

How does the AD7440BRM-REEL7 manage power consumption during low-throughput operation?

The AD7440BRM-REEL7 reduces power consumption during low-throughput operation through two mechanisms: first, dynamic power scales linearly with SCLK frequency-slowing the clock directly lowers IDD; second, it supports a full power-down mode activated by holding CS high, drawing ≤1 μA. This dual strategy enables ultra-low average power in duty-cycled applications such as sensor nodes or portable instruments.

What is the input voltage range for the differential analog inputs of the AD7440BRM-REEL7?

The differential input voltage range of the AD7440BRM-REEL7 is defined as VIN+ − VIN− = ±VREF, yielding a full-scale span of 2 × VREF. Each input (VIN+, VIN−) has an absolute voltage range of VCM ± VREF/2, where VCM equals VREF. For example, with VREF = 2.0 V and 3 V supply, VIN+ and VIN− must each stay within 1.0 V to 3.0 V relative to GND. Exceeding these limits risks damage or invalid conversion results.